1. Field of the Invention
The present invention relates to a device for sampling and pumping liquids contained in a chemical reaction vessel, drum, or storage tank.
2. Description of the Related Art
A particular application of the device of the present invention is in chemical or nuclear industry plants in which it is advisable, particularly during manufacturing processes, to continuously analyze or take samples of liquids that are often noxious, with which the operator should not come into contact, and whose very fumes may be dangerous.
Previously known devices generally include apparatus equipped with conduits for taking samples of liquids using suction systems or suction pumps. However, it is sometimes impossible to use such a sampling device when a reactor is operating under vacuum conditions or when the vapor pressure of the liquid is high. Such a device works well when the liquid in question is under a high vapor pressure.
Another known device is satisfactory but requires several valves, a pressure-fed nitrogen supply, a large pipe network, and a considerable number of components of various types. This sophisticated system requires that it be washed, rinsed with a solvent, and dried by injection of pressure-fed nitrogen after each sampling operation; it is then necessary to eliminate large quantities of contaminated solvent by regeneration or combustion, sometimes at high temperatures, and to clean with a saturated solvent gas, all of which leads to an appreciable increase in pollution of the environment. In addition, the use of a pressure-fed gas presents a potential risk for the operator, primarily due to the possibility of having components or seals burst.
The device disclosed in applicant's cross-referenced related application discloses another device in which the liquid to be sampled is removed from a vessel by a cup which is withdrawn in a closed environment.